#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;

int main(){
    cin.tie(0);
    ios::sync_with_stdio(0);
    
    using ld = double;
    int n; cin >> n;
    vector<ld> dp(1 << 6, 0.0);
    dp[0] = 1.0;
    rep(_,n) {
        vector<ld> nt(1 << 6, 0.0);
        rep(S,1<<6) {
            rep(i,6) {
                nt[S | (1 << i)] += dp[S] / 6.0;
            }
        }
        swap(dp, nt);
    }
    cout << fixed << setprecision(20) << dp[(1 << 6) - 1] << "\n";
}